Fuel pump control means



Aug. 29, v1950 c. H. SCHOWALTER 2,520,356

FUEL PUMP CONTROL MEANS Filed Feb. 10. 1947 Hm I v I INVENTOR CLARENCE H. SCHOWALTER @x mow ATTORNEY Patented Aug. 29,1950

FUEL PUMP CONTROL S Clarence "Schowalter, Beloit, Wis, assignor to Fairbanks, Morse .& 0.0., Chicago, 111., a corporation of Illinois Application February 10, 1947, SeriallNo. 727,518

.8 Claims.

This invention relates to fuel pump control means for internal combustion engines, and is particularly directed to improvements in such control means adapting the same for use in connection with a Diesel engine of the dual fuel character more fully shown and described in a prior application for patent of Clarence H. Schowalte-r, filed on January 11, 1947, and bearing Serial Number 721,549.

The above noted patent application discloses a dual fuel Diesel engine of the two cycle type embodying a fuel control system in which the supply of the liquid fuel is controlled through a governor actuated shaft on which is provided a primary pump control lever and a pilot-fuel control member, the latter actuating a secondary control lever in a predetermined manner to afford establishment Of the pilot-fuel delivery .and the quantity of fuel so delivered. More exact details of this prior control system may be found upon reference to the above mentioned patent application.

In distinction, this present invention is directed objectively to the provision of fuel pump control means of a greatly simplified and commercially inexpensive construction which will accomplish a desirable regulation of the liquid fuel supply pumps associated with a dual fuel Diesel engine, and in which a primary fuel pump control element, operative to afford fuel supply variations during the Diesel operation of the engine, is provided in combination with improved means for establishing a pilot fuel supply during the period of engine operation under dual fuel conditions.

An object of the invention is found in the improved ope-rating characteristics and simple and inexpensive arrangement of means for establishing a pilot-ignition supply of liquid fuel in a Diesel engine operating with gaseous fuel, and in the further improvement of providing means subject to movement of the primary control element in a fuel decreasing sense for effecting actuation of the pilot-fuel supply control means to a no-fuel setting at such time as the engine is to be stopped.

Other objects and advantages will appear from the following detailed description of a presently preferred construction by which the invention may be put into practice, the description relating to the accompanying drawing, wherein:

Fig. 1 is an elevational view of a fuel pump and mechanism for regulating the same, the control regulation thereof being indicated only schematically by an engine operated governor;

Fig. 2 is a view similar to that of Fig. 1 but showing a different phase .of the regulation teffected by the mechanism under governor conrol;

'3 is a detail view of the mechanism taken at line 3-3 in Fig. 1 and'showing the lost-motion interconnection therebetween for accomplishing pump regulation, and

Fig. 4 is a further detailed view, partly in section, of the control means as seen at line 4-4 in Fi 3.

Referring to the drawing, the preferred construction and assembly of the control means is shown in connection with a variable delivery liquid fuel pump Ill of the well known Bosch type, the pump having a fuel supply line H, a delivery line I2 and a rack member l3 which is operativcly carried by the pump and adapted to effect angular adjustments of a constant stroke pump plunger (not shown) whereby the fuel delivery quantigty may be regulated in a manner well understood. The rack member i3 is longitudinally movable into and out of the pump housing for respectively increasing and decreasing the liquid fuel delivery charge, and is normally urged in outward direction by an internally positioned resilient element or spring (not shown) for automatically returning the rack to its outward position for preventing delivery of fuel.

The present pump It is controllably responsive to a fuel demand means, such as the engine oper ated governor M, whereby the fuel delivery may be regulated in accordance with engine load demands. In effecting the desired control response, the governor arm i5 is operatively connected with a fuel control shaft it by means of a crank arm l l secured to the shaft and interconnected with the governor arm I 5 by an-intermediate link it. This last means is only schematically disclosed as it is understood that in actual practice the governor and associated operating mechanism may have a variety of forms and arrangements to suit different conditions.

Governor responsive operation is transmitted through rotation or angular movement of the shaft [5 to the pump control member or rack 13 by means :now to be described in detail. In the preferred arrangement the shaft it carries a primary control member 29, shown as a lever, which is movable from a position out or engagement'with the rack is corresponding to the no fuel setting of the governor M (Fig. 1), into rack engagement for moving the latter inwardly to a maximum fuel delivery position corresponding to the maximum fuel setting of the governor (Fig. 2). Accordingly, the primary member 2-8 is directly operable in response to engine load conditions for regulating the fuel pump. However, in a dual fuel engine of the character set forth in the aforementioned patent application, the conversion from liquid fuel operation to utilization of a gaseous fuel necessitates at least a continued minimum supply of the liquid fuel for initiating combustion of the gaseous fuel. This latter condition of engine operation with a gaseous fuel is preferably carried out, as shown here, by a secondary control member 2| mounted on the control shaft i6 in position to assume command of the pump rack 13 at predetermined times. The secondary member 2|, in the form of a lever, is adapted to have a lost-motion connection (Figs. 3 and l) with the primary lever 28 and to be otherwise movable relative tov the shaft I6 but normally held in an adjustable and substantially fixed position by stop means 22 secured to an adjacent part of the engine frame structure 23. Stop means 22 is adjustably mounted ina sup-. port 2& in position to be engaged by an adjustable stop abutment element 25 carried by the secondary control member 2|. Element 25 is urged into engagement (Fig. 2) with the stop means 22 by a spring 26 which is operatively disposed with one end anchored in the secondary control member or lever 25 and the opposite end anchored in a bracket plate 21 secured to the housing of the pump 10.

More specifically, the interrelated control members 2B and 2| are shown in structural detail in Figs. 3 and 4 wherein the split hub 30 of member 23 is clamped to the shaft l6 and is provided at one face with a lug3l projecting axially therefrom. The control member 2! has a hub 32 which is sleeved on shaft 56 for rotation relative thereto. A locking collar 33, also sleeved on the shaft for securement adjacent the hub of the member 2!, is provided to prevent its axial movement from a desired position closely adjacent the member 20 whereby an axial extending lug 34 formed on the hub 32 of member 2! is adapted to have lostmotion engagement with the first mentioned lug 3! on the hub 30 of member 29. In an arrangement of this character, angular movement of the shaft I6 is directly transmitted to the primary control member 29 while angular movement of the secnodary control member 25 concurrently with member as occurs only upon interengagement of the respective lugs 34 and 3!. While these lugs are out of engagement, the member 29 is automatically held in a predetermined control position by the spring 26 and the abutment of element 25 with stop means 22. This predetermined position is, by preference, chosen such that the outward movement of the pump control rack I3, upon governor actuation of the member 20 in a fuel decreasing direction, is arrested at a pilot fuel delivery setting. Further governor actuation in the same direction will serve to effect complete disengagement of the primary control member 29 with the rack is (Fig. 1).

In the present construction and arrangement of primary and secondary control members'Zii and 2!, it will be noted that the angular relationship of the respective lugs 31 and 34 is such as to provide a period of lost-motion movement of the member 20 independently of member 2! for pump rack control between a full fuel setting and a setting angularly outside of or less than the above mentioned pilot fuel setting as is determined by the position of the secondary member 21. This latter movement of primary member 29 is in effect a limited overtravel movement and is accom- 4 panied by a corresponding range of governor actuation which is not effective to produce any controlling actuation of the pump rack 13. At the end of the overtravel movement of member 20, the lug 3i thereon engages lug 34 on member 2| and thereafter the two members are constrained to move together to the no fuel setting of the governor (Fig. 1).

As viewed in respect to the function of the governor M, the operation of the pump control means from the no fuel setting of Fig. 1 is attended by clockwise movement of member 20 under drive from shaft I6 and concurrent clockwise movement of member 2| under drive from the spring 26, since the spring imposes a constant rotational effort on member 2| which is overcome only upon interengagement of lugs 3| and 34. As the governor rotates shaft [6 toward full fuel position, the member 2| will first engage rack [3, as it is now in a leading angular position relative to member 20. Motion of the member 2| is ventually arrested upon abutment of element 25 with the stop means 22, but motion of the member 2%) can continue, under governor response, through the overtravel range before mentioned and until the lead angle of member 2! is overcome. Thereafter, member 2! remains immobilized and the member 20 continues on to effect rack positionment (Fig. 2) in accordance with the degree of governor responsive actuation to engine load conditions.

With further reference to Fig. 3, in particular, it will appear that the rack engaging end of the member 29 is provided with an angularly adjustable eccentric follower element 36 which is rotationally mounted in the member and held by a lock nut 31. Similarly, an eccentric follower element 38 is rotationally mounted in the member 2! and is held in a desired position of adjustment by a lock nut 39. In a multi-cylinder engine assembly where each cylinder is supplied by its individual fuel pump IE, it is important to achieve a balanced fuel delivery at the pilot fuel setting and at the full fuel setting for smooth and efiicient operation, hence, the provision of adjustable eccentric elements 38 and 36.

The operation of the presently preferred pump control means is now believed fully apparent to those skilled in the art. However, it should be equally apparent that the control of a fuel pump to provide a range of fuel delivery variations, a range of limited fuel delivery and a complete cessation of fuel delivery may be accomplished by means other than that described in connection with the accompanying drawing. Accordingly, the present control means is primarily intended to afford an instructive disclosure of the invention, the full intended scope of which is more particularly set forth in the appended claims.

I claim:

1. Control mechanism for a variable delivery fluid pump, said mechanism including a primary control member operably associated with the pump and arranged for control movement to effect variations in the delivery of fluid and for movement to a position terminating pump fluid delivery, a secondary control member operably associated with the pump for movement to a position effective to establish a predetermined and limited delivery of fluid, and means responsive to movement of said primary control member to said position terminating pump fluid delivery for effecting movement of said secondary control member to a position out of pump control association. r

2. Control mechanism for a variable delivery fluid pump, said mechanism comprising an element operativey associated with the pump for effecting delivery variations thereof, first control means engageable with said element to effect operation thereof to a position of limited fluid delivery from the pump, second control means operatively arranged for movement into engage ment with said element from a position disengaged therefrom for effecting variations in the fluid delivery in excess of said limited delivery, and means movable with said second control means for effecting movement of said first control means in a direction to disengage said element upon movement of the second means to its disengaged position, thereby terminating fluid delivery by the pump.

3. Control mechanism for a variable delivery fluid pump, said mechanism including an element movably carried by the pump and arranged for effecting fluid delivery variation thereof, a first control member movable into engagement with said element to move the same to a position of predetermined limited fluid delivery, a second control member movable into engagement with said element to move the same in a manner for effecting variations in the delivery of fluid, and means movable with said second member and arranged to have engagement with said first mem her for moving the same out of engagement with said element following disengagement thereof by said second member, whereby to terminate fluid delivery by the pump.

l. Control mechanism for a variable delivery fuel pump, comprising in combination, a primary control member angularly movable from a no fuel delivery position into operative control relation with the pump for effecting delivery variations thereof, a secondary control member angularly movable from a no fuel delivery position in.- to operative control relation with the pump for determining a limited fuel delivery by the pump, and a lost-motion operative connection between said control members for permitting independent angular movement of said primary member to effect pump delivery variations in excess of the limited delivery afforded by said secondary member, and concurrent angular movement of said control members to the respective no fuel positions thereof.

5. Control mechanism for a variable delivery fuel pump, comprising in combination, first con= trol means for effecting a variable regulation of the pump delivery toward and from a maximum delivery control condition thereof, said first con trol means being movable to a position out of delivery regulating relation with the pump for terminating delivery therefrom, second control means for eifecting a constant limited pump delivery regulation, means adapted to urge said second control means into pump regulating position independently of said first control means, and means movable with said first control means for engaging and actuating said second. control means against said urging means and out of pump delivery control regulation, upon movement of said first control means to said position out of pump delivery regulating relation.

6. Control mechanism for a variable delivery fuel pump of the character described comprising 1 nection between in combination with a governor actuated control shaft which is responsive to fuel demands, a primary control member carried by the shaft and movable therewith from a position out of pump delivery regulating relation into a range of variable delivery regulation thereof in accordance with fuel demand response of the governor, a secondary control member mounted on the shaft, means normally urging said secondary member into pump delivery regulating relation in advance of said primary member, other adapted to arrest said secondary member at a predetermined positicn of pump regulation to afford a limited delivery therefrom, and an operating conprimary and secondary members for effecting movement of said secondary member in opposition to said urging means and. out of pump regulating relation in response to movement of the primary member into said position out of pump regulating relation.

'7. In a fuel pump control mechanism, the combination of a control shaft adapted for angular movement in accordance with demands for fuel, a primary control lever fixed on said shaft and movable therewith between a range of effective pump delivery regulation and a position out of pump regulating relation, a secondary control lever sleeved on said shaft, means resiliently urging said secondary lever in an angular direction for effecting pump delivery regulation, stop means for arresting the angular movement of said secondary lever at a predetermined position of pump delivery regulation for establishing a limited delivery of fuel by the pump, and an operating connection between said primary and secondary levers for effecting movement of the secondary lever against said resilient means and out of pump regulating relation upon movement of the primary lever into its position out of pump regulating relation.

8. In a fuel pump control mechanism of the character set forth in claim 7, and further characterized in that said operating connection between said primary and secondary levers is adapted and arranged to afford movement of said primary lever out of its range of pump regulating relation in advance of movement of the secondary lever against said resilient means, and conversely to afford movement of the secondary lever by said resilient means into said predetermined arrested position for limited fuel delivery regulation in advance of the movement of the primary lever into its range of effective pump regulating relation.

CLARENCE H. SCHOWALTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,981,734 Kuttner Nov. 20, 1934 2,200,459 Thomas May 14, 1940 2,222,593 Hurst et al. Nov. 26, 1940 2,241,096 McCullough May 6, 1941 2,259,693 Hogeman Oct. 21, 1941 2,307,974 Turner Jan. 12, 1943 2,331,577 Somtag Oct. 12, 1943 

